Method of producing air permeable pile fabric



Nov. 8, 1938. s HlERs 2,135,712

METHOD OF PRODUCING AIR PERMEABLE PILE FABRIC Filed Dec. 17, 1936 83A a C7 FIG. 1

INVENTOR GLEN 5. H/EQS.

ATTORNEY Patented Nov. 8, 1938 UNITED STATES PRODUCING AIR PERIVIEABLE PILE FABRIQ I LIETHOD OF PATENT OFFICE Application December 17, 1936, Serial No. 116,274

2 Claims.

My invention relates to the manufacture by a continuous process of air permeable 'pile fabrics having pile tufts or loopslooped over the wefts of a somewhat sleazy backing fabric during the fabrication thereof, and secured against dis-. placement or relative movement thereto by the solidification of the solidifiable constituents of a thickened aqueous dispersion of latex or like material applied to the backing and that portion of the tufts which liein the plane of the backing through the back of the fabric. Impregnated fabrics having a dense pile face yet permeable to air may be produced by the here inafter described method.

It is known that a V-pile weave permits of securing greater'coverage for a given length of pile yarn, which may be wool or other animal fibres, such as mohair, or vegetable fibres including cotton and/or blends of thesefibrestogether or with synthetic fibres, than the w or fast pile loop and the objectionable grinning through of the knees of the W tufts is also avoided. Ordinarily, it is not necessary to resort to impregnating the backing and/or tufts of a W pile weave with an adhesive but in very loosely woven fabrics, this may be advantageous.

More particularly, the invention is directed to controlling the depth of penetration and the location of an impregnating adhesive binder material in a. pile fabric so that the pile portion of the fabric is securely anchored in position and the fabric maintains its textile appearance and feel on both face and back side.

An object of the present invention is to improve upon the hitherto known methods of impregnating the backing of a pile fabric by the removal of water repellent substances naturally or artificially present or incorporated in the yarns comprising the fabric by a scouring process and then simultaneously or otherwise removing free water and/or partially. drying and straighten ng the fiDl'eS of the pile to condition the fabric for the subsequent impregnating step.-

The water-repellent substances normally present in the fibres, and which tend to weaken the bond of the binder material, may be the natural waxes, oils, pectins or resins present in either or both animal and vegetable fibres or may be lubricants applied to these or other fibres in the spinning or processing thereof.

In the practice of this invention it is preferable to eiiect the removal of the water repellent substances prior to impregnation of the backing fabric and an important object of this invention is to condition a pile fabric during its passage from the scouring vats or chambers to the coatingdevice. This conditioning includes a removal of the free scouring or rinse liquid and a raising and partial repositioning of the pile tufts or fibres with the result that a more satisfactory and uniform finished product results.

The scouring of the fabric may be accomplished with a detergent solution of soap, ammonia, soda, or other alkali, or with suitable oil solvents, which may be of the chlorinated type emulsified with water. If the fibres used are naturally free from deleterious amounts of water-repellent substances, a water soluble lubricantsuch as diethylene glycol or its homologs or derivatives may be used in thepreparatory process and spinning of the fibres and'oily lubricants generally used may be dispensed with. The removal of such water soluble lubricants may be effected by treatmentof the fabric with water alone.

When the water-repellent substances have been eliminated or reduced in amount to a desired degree from the fabric and the fabric conditioned to effect a control of the penetration and location of the binder material, it may be impregnated with an'aqueous material containing a solidifiable constituent such as latex,artificial aqueous dispersions of rubber, or synthetic rubber derived from chloroprene or aqueous dispersions of pyroxylin or other cellulose derivatives.

In the accompanying drawing:

Fig. I is a diagrammatic illustration of apparatus suitable for the practice of my process and; I V

Fig. II is a diagrammatic view of a V.pi1e tuft a and its corresponding weft b and warp threads c.'

The type and condition of the yarns in the woven fabric permitting, it is preferred to dehydrofuge a pile fabric in accordance with the method illustrated diagrammatically in Fig. I, wherein the fabric A is run through a general treating bath Ill and over and under rollers H and I2. Rollers ll may be wholly or partly submerged in the baths or above them. A set or a plurality of sets of driven nip rollers [3 act to press the treating liquids out of the fabric and to move the fabric forward. The nip rollers are so positioned as illustrated in Fig. I that the solution of one bath with the exception of that carried by the moving fabric is prevented from entering the next sequential compartment. This general bath is divided into a plurality of compartments, H, l5 and Hi. The compartment l4 may contain an alkali and soap solution such as type of bath may be suitable proportions of sodium oleate soap and trisodium phosphate in pre-heated water; compartment IS, a soap solution; It, a rinse. It is obvious that a plurality of each used and that one or more rinse baths may cool the fabric down from the temperature it has when it leaves the earlier compartments to approximately atmospheric temperature. When the fabric leaves the rinsing compartment, it is passed around roller l9 and over a vacuum hydro-extractor II, which removes surplus water from the fabric and from the interstices betweenthe threads. The fabric may then be moved directly, without being dried, to the impregnating apparatus whereit is impregnated and subsequently dried or vulcanized. The hydro-extractor l1 above referred to is an important feature of this invention and serves a dual function. It will be seen from Fig. I that the face or pileside of the pile fabric passes over the face of the hydro-extractor l1 and that a current of air as indicated by the arrows passes through the fabric from the back to the face side to straighten the fibres because a substantial vacuum of approximately 20" of mercury is created by the extractor H. A heating unit l8 may be mounted opposite the extractor unit in which case warm or hot air will be drawn through the fabric and further reduce'the moisture content at this point, and during the passage of the fabric to the impregnating apparatus air may be blown through the fabric from the back through the face but the vacuum arrangement above described is the preferable embodiment. An effective control of the water content of the treated or dehydrofuged fabric accordingly results. In pile fabric containing animal fibre pile it is preferred that the water content be below per cent of the dry weight of the fabric in all cases where controlled penetration is desired but the exact percentage is governed largely by the character and viscosity of the binder material used.

An example of the moisture-binder viscosity control relationship as contemplated by this invention for a fabric having a cotton backing and a pile of mohair is as follows: A V-pile fabric consisting of 3600 warp ends of 2/40 cotton yarn in 57 inches of width of fabric and 46 picks per inch of 1/12 cotton weft over which is looped a mohair pile tuft from yarn of 2/40 count for each 4 of the backing warp ends may be impregnated as herein described with an aqueous dispersion of latex of approximately 30 per cent solid content, 3 per cent of which is compounding material, and the remaining 27 per cent rubber, said composition having a Viscosity of 600 centipoises. Highly desirable results with this fabric areobtained by reducing the water content to approximately 52% fabric by means of the hydro-extraction I1 and/or heating unit l8. The most desirable water content will of course vary with different weaves or binder compositions.

.After conditioning, the fabric A is passed over rollers I9, 20 and 21 in transit to the impregnating apparatus. Any tufts which have been materially loosened by the treatment for the removal or neutralization of the hydrofuge substances are brushed off by the brush 22 and slightly loosened tufts are forced back into position by the roller 23 and stationary cylinder 24 on opposite sides of the card clothing roller 25. The card clothing rollers 25 and 26 are provided with wire teeth which support the backing withand compartment Y by weight of the dry out applying pressure to the pile tufts. In passing from the card clothing roller 25 to the card clothing roller 26, the fabric passes beneath a blade 21 to which the baffle plate 28 discharges a layer of uniform thickness of a hydrosol, such as latex containing a solidifiable constituent, and is discharged to the baffle plate through cocks 29 of an adjustable reservoir 30. The hydrosol is forced into the yarns of the fabric by the action of the blade 21 and of the roller 3! so as to leave the interstices of the fabric open and the bights of the pile tufts exposed to form a nodulous surface imparting to the fabric a textile feel and handle. The hydrosol permeates into the backing, without passing therethrough to the pile face of the fabric and is solidified or vulcanized primarily in the backing by the passage of the fabric through a tenter drier 32 while stretched by the engagement of its selvages by the pins of tenter chains 33. The blade 21 may be of conventional or special design depending on the characteristics of the particular fabric being impregnated. Its function is to force the adhesive by a swirling action or otherwise into the fabric and to clean off the tips of the pile bights a of the fabric and thereby locate the adhesive so that an improved flexible pile fabric having a normally insoluble binder composition confined substantially within the perimeters of the backing threads and that por tion of the tufts which is in the plane of the backing with the binder material being in contact with a majority of the individual fibres of both the backing thread and pile tufts and not filling the interstices between the threads may be produced. A fibre lock as opposed to a thread lock is thus obtained as shown in Fig. II. A few discrete particles d remaining on the tips of the bights will not deleteriously affect the air permeability of the fabric and may be advantageous in subsequent automobile body work assembly, but as hereinbefore set forth, a skin coating of adhesive is deleterious to air permeability and to subsequent cutting and sewing operations when the fabric is being worked.

By the steps of removing or neutralizing waterrepellent substances in the yarns, which for brevity has been called dehydrofuging the yarns, an intimate contact is secured between the solidifiable constituent of a hydrosol and the fibres of the fabric and I avoid the formation of a surface skin on the yarns or fabric, and also improve the anchorage of the pile tufts to the backing and th backing yarns to one another, with consequent improvement in the durability as well as in the appearance of the fabric, the use of less rubber and so economies are effected, better tensiles and elasticities are produced due to absence of oil absorption, and better-ageing properties.

Having described my invention, I claim:

1. In the manufacture by a continuous process of an impregnated air permeable pile fabric having pile elements looped about wefts of a somewhat sleazy woven backing, said pile elements originally containing water repellent bond inhibiting substances, the steps of removing the bond inhibiting substances by wetting the pile fabric, scouring the pile fabric with a suitable detergent, rinsing the pile fabric, passing the wet fabric adjacent to and substantially in contact with an air extractor employing a strong current of air which current passes through the fabric whereby rinse liquid is removed from the fabric and the interstices of the fabric are left open,

thesame current of air which removes the rinse liquid also" acting to straighten or lift the pile, brushing the fabric to remove loose pile tufts and force slightly loosened pile tufts back into the fabric, depositing a uniform layer of an hydrosol on the back of said fabric, forcing the hydrosol into the fabric, leaving the interstices of the fabric open and the bights of the pile'exposed to form a noduloustsurface imparting a textile feel and handle to the fabric, the quantity of hydrosol being controlled so that it is substantially confined to the plane of the woven backing, and setting thehydrosol ereby the pile is adhered to the backing. Y

2. In the manufacture by a continuous process of an impregnated air permeable pile fabric hav. ing pile elements looped about weftsbf a somewhat sleazy woven backing, said pile elements originally containing water repellent bond inhibiting substances, the steps of removing the bond inhibiting substances by wetting the pile fabric, scouring the pile fabric with, a suitable detergent, rinsing the pile fabric, passing the wet fabric adjacent to and substantially in conon the back of said fabric, forcing the hydrosol into the fabric, leaving the interstices of the fabric open and bights of the pile exposed to form I a. nodulous surface imparting a textile feel and handle to the fabric, the quantity of hydrosoi being controlled so that it is substantially confined to the plane of the woven backing, and setting the hydrosol whereby the pile is adhered to the backing.

" I GLEN S.'HIERS. 20 

